Experimental investigation of transient grounding resistance characteristics on the radialized grounding electrode

The characteristics of transient voltage, current and grounding resistance of two kinds of radialized grounding electrodes were investigated based on field measurements. Each kind of grounding electrode was made of reinforcing steel bars with diameter of 10 mm, and had the same total length of 16 m, and were buried horizontally at the depth of 0.6 m from the ground surface. The star-shape grounding electrode was composed of 8 reinforcing steel bars; The cross-shape one was composed of 4 reinforcing steel bars. A transient discharge from a high-voltage pulse generator was applied at the center of the grounding electrode to observe transient voltage and current on it. The measured waveforms were synchronously recorded, the transient grounding resistance was calculated and analyzed. From the experiment results, we can see the obvious capacitive characteristic on the star-shape grounding electrode. We can also see the accordance between the stable value of TGR and the theoretic value of power frequency ground resistance.